The invention relates to a rail vehicle with pivotal front and rear undercarriages, guided on both sides along guide rails by means of front and rear guide wheels, and connected directional guide wheels which follow directional guide rails arranged in branch switch connections, and with those directional guide wheels on each side of the undercarriage connected by means of shift linkages. Reference is made to U.S. Pat. Nos. 3,828,691 and 4,000,700, which are hereby incorporated by reference in their entirety.
German Pat. No. 2 427 870 disclosed a rail vehicle where each undercarriage is provided on both sides in front and rear with guide wheels and directional wheels which are not mechanically connected for purposes of shifting gears. Therefore, faulty switching may occur. Since the guide wheels in branch areas only adhere to guide rails on one side while the guide rails arranged on the other side of the rail recede, the rear undercarriage, too, must be equipped with directional wheels for proper guidance. If vehicles are very long it may be, particularly when branch lines follow at brief intervals, that a switch impulse for the directional wheels is given when the front directional wheels have already passed the branch, while the rear directional wheels follow the switch impulse. This inevitably leads to accidents.
It is therefore the object of the invention to provide a rail vehicle which has front and rear undercarriages including directional wheels, in such a manner that faulty switching between the two is avoided. This is done by connecting all directional guide wheels of each undercarriage of the vehicle in both the front and rear undercarriages with one another for the purpose of shifting. Before entering a switching area, be it in diverging or converging direction, all directional guide wheels are aligned in one of the two possible positions. A switch-over of some of the directional wheels while passing the branch is not possible since the directional rails provided there will not allow any pivoting movement.
Furthermore, the connection for shifting is positioned in the longitudinal center axis of the rail vehicle so that changes in length resulting during the passing of curves from the tilting of the undercarriages vs. the rail vehicle do not influence the shifting in any way. The connection is, preferably, made by means of a rod whose ends rest on levers. Each lever consists of a two-arm toggle lever positioned in the center longitudinal axis and pivoting around a vertical axis in said center longitudinal axis. Each toggle lever has one lever arm connected to the rod and the other lever arm being connected to the related linkage. The rod, together with the levers, makes up a secure connection between the directional wheels on the front and rear undercarriages and connected to one another via the shift linkages.
The shifting connection may also consist of a rod crossing the longitudinal center axis, its ends resting on uniformly long levers arranged in the longitudinal center axis of the undercarriages and connected to the shift linkages. This rod may also be replaced by two crossing cables. Furthermore, the shifting connection may be made by two adjacent Bowden control cables whose ends engage with two-arm levers connected to the shift linkages. Even a single Bowden control cable may make the connection, if there is no chance of buckling of the free wire end.
Two examples of the invention are shown on the drawings and explained as follows: